We are currently using KONOS curriculum. It is most benficial if you watch the Creating the Balance videos to fully understand. You can buy these new from KONOS or like I did from Amazon. These videos have much helpful information for all homeschoolers and I learned a ton even after homschoooling our kids for 8 years.
Cruising through school :) with KONOS
One of my favorite places to purchase curriculum and school supplies is from Rainbow Resource. There is a review/descripition of every item they sell. Their prices are very competitive and they have an excellent, personable staff.
My favorite workbooks for elementary level are Scholastic "Success With _____ Grade" for covering most everything in the elementary grades. They are an excellent supplement and go-to book.
The other workbooks I love are the Kumon workbooks, which are reasonably priced. Most are 4.75 or 5.50 each.
Homeschool Share is a cool site with lots of lapbooking freebies, unit study freebies,Five in a Row resources, and wonderful ideas.